1. Field of the Invention
The present invention relates to an apparatus for probing multiple devices under test, and more particularly, to a probing apparatus for acquiring electrical properties of a plurality of integrated circuit devices under test simultaneously.
2. Description of the Related Art
In the manufacturing process of integrated circuit devices, a probe card is used to probe electrical properties to sieve out integrated circuit devices that do not meet the product specifications. Traditionally, the probe card is designed according to the specification and the position of signal pads of the device under test, each probe is positioned on a supporter, and epoxy resin is used to adhere the probe onto the supporter. The probe card is then positioned on a printed circuit board conforming to the device under test. Finally, the position of each probe is precisely adjusted to meet the specification of the device under test in order to carry out accurate and steady electrical testing.
FIG. 1 is a sectional view of a probe card 10 according to the prior art. As shown in FIG. 1, the probe card 10 comprises a circuit board 12, a supporter 14 positioned on the circuit board 12, a plurality of probes 16 fixed on the supporter 14, and a via hole 20 electrically connected to the probe 16 and a wire 26. In order to prevent the horizontal position of the probe 16 from shifting by the increased service time, the probe 16 is fixed on a supporter 14 by epoxy resin 24. When probing the electrical properties of an integrated circuit device 30, the probe card 10 is positioned on a testing machine (not shown in FIG. 1). The testing machine moves the probe card 10 to form an electrical contact between the signal site 38 of the probe 16 and the integrated circuit device 30 so that testing signals can be transmitted.
However, once the probe card 10 is completed, it can only be used to probe the electrical properties of integrated circuit devices with the same specification. If the arrangement or distance of the signal pad of a new integrated circuit device is different from that of the integrated circuit device 30, a new probe card has to be manufactured for the new integrated circuit device. Therefore, the traditional probe card 10 does not possess any flexibility to be applied to different integrated circuit devices; hence the testing cost cannot be lowered.
Furthermore, since new technology dramatically shortens the time and process for fabricating the integrated circuit device, how to efficiently control the testing time becomes a key in controlling the entire manufacturing time of the integrated circuit device. Consequently, many companies manufacturing the probe card have recently attempted to perform the testing of multiple devices at the same time by changing the way of arranging the probes so as to shorten testing time of integrated circuit devices. However, all these manufacturing companies meet the same problem that the relative position between probing points is fixed, even for the probe card capable of performing multiple device testing. For example, if the probe card is designed to test four adjacent integrated circuit devices simultaneously, the user has to replace the probe card to test four integrated circuit devices not adjacent to each other or with different relative positions, i.e., there is no flexibility for applying the probe card to other devices. As a result, the manufacturer must prepare a new probe card, which costs extra time and money, and the testing time of the integrated circuit device cannot be decreased.
FIG. 2 to FIG. 4 are schematic diagrams of a probing apparatus according to the prior art, disclosed in U.S. Pat. No. 6,011,405. As shown in FIG. 2, a plurality of probes 42 are positioned on a wedge card 40, which is positioned on a manipulator 44 of the probing apparatus. Turning the screw 45 will move the manipulator 44 along the z-axis to adjust the relative vertical position between the wedge card 40 and a device under test.
Please refer to FIG. 3, in which both ends of a rod 70 are positioned on two parallel platen 60 through two manipulators 74, both ends of another rod 72 are positioned on another two parallel platen 60 through two manipulators 76, and a manipulator 66 is mounted on the two orthogonal rods 70, 72. That is to say, two sets of parallel platens 60 enclose an opening 64, while the two orthogonal rods 70, 72 are positioned on the parallel platens 60. The wedge card 40 is positioned on the manipulator 66, and the relative position along the x-axis and y-axis between the probe 42 on the wedge card 40 and a device under test can be adjusted by moving the two orthogonal rods 70, 72 on the platen 60 along the x-axis and y-axis. Since the abovementioned design uses a round rod to bear the manipulator 66, it needs two orthogonal rods 70, 72 to prevent the manipulator 66 from overturning.
As shown in FIG. 4, the abovementioned design can increase the number of the manipulator 66 and the two orthogonal rods 70, 72 to implement the multi-dies testing simultaneously. However, the manipulator 66 must be supported by two orthogonal rods 70, 72, which restrict the manipulator 66 to move along the x-axis and y-axis. For example, three manipulators 66 on the same rod 70 must be at the same position along the y-axis, while three manipulators 66 on the same rod 72 must be at the same position along the x-axis. In other words, the abovementioned design is only suitable to probe the electrical properties of the integrated circuit device arranged in an array manner. If the integrated circuit device is not arranged in an array manner, individual orthogonal rods 70, 72 are needed to support each manipulator 66 so that the abovementioned design can be applied. Consequently, not only does the complexity of the design increase, but also the number of the integrated circuit devices under test simultaneously decreases.